Manual installation tutorial

Step by step

In order to develop on decidim, you’ll need:

  • Git 2.15+

  • PostgreSQL 9.5+

  • Ruby 2.5.0 (2.3+ should work just fine, but that’s the version we test against)

  • NodeJS 15.14.x

  • Npm 7.7.x

  • ImageMagick

  • Chrome browser and chromedriver.

We’re starting with an Ubuntu 16.04 LTS. This is an opinionated guide and YMMV, so if you’re free to use the technology that you fell most comfortable on. If you have any doubts and you’re blocked you can go and ask on our Gitter. We recommend that you follow some Ruby on Rails tutorials (like Getting Started with Ruby on Rails) and have some knowledge on how gems and engines work.

On this tutorial we’ll see how to install rbenv, PostgreSQL and Decidim, and how to configure everything together.

Installing rbenv

First we’re going to install rbenv, for managing various ruby versions. We’re following the guide from DigitalOcean. You could also use rvm as an alternative on this step. On these instruction we’re using the latest ruby published version at the moment (2.5.3), but you should check this out on Ruby official website.

sudo apt update
sudo apt install -y build-essential autoconf bison libssl-dev libyaml-dev libreadline-dev zlib1g-dev libncurses5-dev libffi-dev libgdbm3 libgdbm-dev libicu-dev
git clone ~/.rbenv
echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
echo 'eval "$(rbenv init -)"' >> ~/.bashrc
source ~/.bashrc
git clone ~/.rbenv/plugins/ruby-build
rbenv install 2.5.3
rbenv global 2.5.3
echo "gem: --no-document" > ~/.gemrc
gem install bundler

Installing PostgreSQL

Now we’re going to install PostgreSQL for the database:

sudo apt install -y postgresql libpq-dev
sudo -u postgres psql -c "CREATE USER decidim_app WITH SUPERUSER CREATEDB NOCREATEROLE PASSWORD 'thepassword'"

You need to change the password (on this example is "thepassword") and save it somewhere to configure it later with the application.

Installing Decidim

Next, we need to install the decidim gem:

gem install bootsnap
gem install listen
gem install decidim

Afterwards, we can create an application with the nice decidim executable, where decidim_application is your application name (ie

decidim decidim_application
cd decidim_application

We recommend that you save it all on Git.

git init .
git commit -m "Initial commit. Generated with Decidim 0.X"

Configure the database

You need to modify your secrets (see config/database.yml). For this you can use figaro, dotenv or rbenv-vars. You should always be careful of not uploading your plain secrets on git or your version control system. You can also upload the encrypted secrets, using the sekrets gem or if you’re on Ruby on Rails greater than 5.1 you can do it natively.

For instance, for working with figaro, add this to your Gemfile:

gem "figaro"

Then install it:

bundle install
bundle exec figaro install

Next add this to your config/application.yml, using the setup the PostgreSQL database name, user and password that you configure before.

DATABASE_HOST: localhost
DATABASE_PASSWORD: your_password

Finally, save it all to git:

git add .
git commit -m "Adds figaro configuration management"

Initializing your app for local development

We should now setup your database:

bin/rails db:create db:migrate
bin/rails db:seed

This will also create some default data so you can start testing the app:

  • A Decidim::System::Admin with email and password decidim123456, to log in at /system.

  • A Decidim::Organization named Decidim Staging. You probably want to change its name and hostname to match your needs.

  • A Decidim::User acting as an admin for the organization, with email and password decidim123456.

  • A Decidim::User that also belongs to the organization but it’s a regular user, with email and password decidim123456.

This data won’t be created in production environments, if you still want to do it, run:

SEED=true rails db:setup


When you run bin/rails db:migrate you should see a lot of output. If you don’t, or if you run into errors seeding your database, try runnning bin/rake decidim:upgrade before.

You can now start your server!

bin/rails s

Visit http://localhost:3000 to see your app running. 🎉 🎉